1. Field
The present disclosure relates to turbomachines, and more particularly to turbomachine blade clearance.
2. Description of Related Art
Turbomachines are meticulously designed to have minimal clearance between the outer edges of the blades and the inner surfaces of the turbomachine casing. With more clearance comes more aerodynamic inefficiency in the blades. Turbine blades, for example, have a series of TBC (Thermal Barrier Coatings) coated plates surrounding each rotor stage. Initially, the ceramic contacts the outer edge of the plate and is abraded to form fit the turbine blade. However, even such tightly engineered technology cannot prevent the relative differential thermal expansion of the turbomachine blades and surrounding components, leading to a gap or excessive contact under certain operability conditions. The clearances between the blades and seals are typically oversized for normal operation to prevent rubbing in more extreme conditions. The oversizing of these gaps represents a loss in the overall engine cycle efficiency. Determining the distance of clearance can be difficult and require separate waveguides, wires, and complex circuitry which can add weight and reduce the value of the entire clearance system.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for a system to improve sealing of turbine blades and measurements of gap distance, for example. The present disclosure provides a solution for this problem.